One of NASA’s small fleet of space-based telescopes has captured an X-ray image of the ominous glow of two black holes that dwell in the center of a spiral galaxy. The Nuclear Spectroscopic Telescope Array’s, or NuSTAR’s, image was released on Monday, Jan. 7, 2013. The image of supernova remnant Cassiopeia A was unveiled at the American Astronomical Society, which was held in Long Beach, Calif.
“These new images showcase why NuSTAR is giving us an unprecedented look at the cosmos,” said Lou Kaluzienski, NuSTAR program scientist at NASA headquarters in Washington. “With NuSTAR’s greater sensitivity and imaging capability, we’re getting a wealth of new information on a wide array of cosmic phenomena in the high-energy X-ray portion of the electromagnetic spectrum.”
NuSTAR roared into space in June 2012 atop an Orbital Sciences Corporation Pegasus XL rocket from Kwajalein Atoll, located in the Pacific Ocean.
The space-based telescope can see in exquisite detail, as it is capable of focusing high-energy X-ray light. NASA has been tweaking NuSTAR to maximize its potential.
The telescope has been aimed at a number of potential black holes and has conducted research on these super-dense objects at the core of our home galaxy—the Milky Way.
However, black holes are just part of NuSTAR’s mission. The telescope has also imaged the spiral galaxy IC 342, also known as Caldwell 5, which was previously imaged by one of NASA’s “Great Observatories”—the Chandra X-Ray Observatory. Chandra detected incredibly bright black holes, which have been named ultraluminous X-ray sources, or ULXs.
It is not clear why ULXs shine as brightly as they do. They are not as powerful as supermassive black holes, which exist at the core of galaxies yet are ten times brighter than stellar-mass holes that are common throughout our galaxy.
“High-energy X-rays hold a key to unlocking the mystery surrounding these objects,” said Fiona Harrison, NuSTAR’s principal investigator at the California Institute of Technology in Pasadena. “Whether they are massive black holes, or there is new physics in how they feed, the answer is going to be fascinating.”
NuSTAR has opened a new realm of research into these incredible objects.
“Before NuSTAR, high-energy X-ray pictures of this galaxy and the two black holes would be so fuzzy that everything would appear as one pixel,” said Harrison.
Besides the image of the black hole, NuSTAR also imaged the supernova remnant Cassiopeia A, which can be found some 11,000 light-years distant in the constellation Cassiopeia. The blue color indicates the regions with the highest concentrations of energy, as well as the shock wave from the supernova’s eruption as it hammers into the surrounding material, which is comprised primarily of dust and gas.
“Cas A is the poster child for studying how massive stars explode, and also provides us a clue to the origin of the high-energy particles, or cosmic rays, that we see here on Earth,” said Brian Grefenstette of Caltech, a lead researcher on the NuSTAR project. “With NuSTAR, we can study where, as well as how, particles are accelerated to such ultra-relativistic energies in the remnant left behind by the supernova explosion.”